What is “rare earth” and how is it bad for the environment?

Answers

There are actually a number of elements in the periodic table that are considered to be “rare earth”, including lanthanum and actinium. They are not considered to be truly rare but simply until 1945 very difficult to purify from their oxides. Rare earth metals are silver, silvery-white, or gray in color and have high electrical conductivity. Some of these metals are very important in newer technology, such as hybrid and electric vehicles. It is the mining of these elements that poses an environmental threat.